We knew what was going to happen because we’ve seen it before. Several times. So how in the world did the San Francisco 49ers not know what was coming?

It might as well be in the Kansas City Chiefs’ playbook for Super Bowls: Play poorly, fall behind by double digits and, almost always, come back and win. It happened the first time the Chiefs and the Niners played. It happened last year against the Philadelphia Eagles.

And it happened again Sunday night, with Patrick Mahomes and the Chiefs erasing a 10-point, first-half deficit, tying the game twice in the last 5:49 to force overtime and then winning it with a cold-blooded drive that snatched the very souls out of San Francisco and its fans. It's the second consecutive Super Bowl title for the Chiefs, the first team to repeat in 20 years, and their third since 2020.

And the 49ers have nobody to blame for the loss but themselves.

Not because it was scripted or Travis Kelce’s girlfriend is a psyops or any of the other nonsensical conspiracy theories floated by right-wing provocateurs who are terrified of powerful women and happy people. It’s because San Francisco didn’t learn a darned thing from the last time these teams met in the Super Bowl, a whopping four years ago.

CHIEFS FANS: Here’s where you can buy the Super Bowl 58 commemorative cover

The Niners had the Chiefs on the ropes for almost the entire first half. Mahomes looked mortal, Kelce looked as if he was melting down and the normally stout offensive line looked porous. Their first four drives went punt-punt-fumble-punt, and they gained a combined 79 yards on them — most of which came on the series that ended with a red-zone fumble.

San Francisco, meanwhile, was shredding the Kansas City defense. Christian McCaffrey was doing Christian McCaffrey things, and Brock Purdy had what seemed like hours to throw.

The one thing the Niners weren’t doing was scoring points, stopping themselves repeatedly with silly penalties. At halftime, the 49ers were up 10-3 but it easily could have been 30-3.

And it should have been, given who they were playing.

“It wakes us up a little bit. Gives us that spark we need,” Mahomes said of facing a double-digit deficit yet again in the Super Bowl.

“We could make it easier,” he added, “but what’s the fun in that?”

MORE: Patrick Mahomes wins Super Bowl MVP for third time after pushing Chiefs to thrilling OT win

Fun for Mahomes and the Chiefs, a nightmare for their opponents. If anyone should have been ready for this fever dream, however, it was San Francisco.

When the teams played four years ago, they were tied at halftime. Then Jimmy Garoppolo and the Niners came out cooking with gas in the third quarter, hanging 10 unanswered points on the Chiefs. Kansas City, meanwhile, was a mess, with Mahomes throwing interceptions on the Chiefs’ first two possessions of the second half.

You know the rest of the story. Mahomes threw for one touchdown and then another. Damien Williams ran in for a third score, the defense picked Garoppolo off and the Chiefs had the first of what is now three Super Bowl titles in five seasons.

And now Mahomes has done it to the Niners again.

Mahomes and the Chiefs outgained San Francisco by almost 100 yards in the second half and overtime. Though Mahomes didn’t throw his first touchdown until late in the third quarter — 2:32 to go, to be exact — he kept the Chiefs close to the Niners, never allowing them to pull away.

OPINION: Patrick Mahomes and Chiefs leave no doubt in Super Bowl: They're an all-time NFL dynasty

“The offense came through with plays when we needed them,” Mahomes said.

When San Francisco was forced to kick a field goal on the first possession of OT, everyone at Allegiant Stadium or watching at home knew how this was going to end. No, we weren't peeking at some non-existent script. We just know Mahomes is going to do what Mahomes always does in these situations.

Sure enough, facing a fourth-and-1, Mahomes converted with an 8-yard run. Six plays later, he broke free for a 19-yard gain and all that was left was to engrave the Lombardi Trophy.

Mahomes' second-half dominance earned him Super Bowl MVP honors. He joins Tom Brady and Joe Montana as the only players to win the award three times.

“We never stopped believing,” Mahomes said. “We never stopped believing.”

Of course they didn’t. When Mahomes and the Chiefs are in the Super Bowl, everybody knows no lead is safe.

And if the Niners didn't, well, that's on them.

Follow USA TODAY Sports columnist Nancy Armour on social media @nrarmour.

This article originally appeared on USA TODAY: Chiefs' fun was a nightmare for 49ers. Why didn't they see it coming?